cuelang.org/go@v0.13.0/encoding/jsonschema/testdata/external/tests/draft2020-12/optional/format (about) date-time.json date.json duration.json email.json hostname.json idn-email.json idn-hostname.json ipv4.json ipv6.json iri-reference.json iri.json json-pointer.json regex.json relative-json-pointer.json time.json unknown.json uri-reference.json uri-template.json uri.json uuid.json